Sometimes, as our visiting students hike through thick piles of leaves covering the trails, they ask—where do the leaves go after they fall? When all the leaves on lawns and sidewalks are raked and bagged up, it’s hard to notice that, out on our trails, large piles of leaves seem to be magically cleared away by the time spring rolls around. We also have rotting apples in the orchard, dead plants in the shrub layer, and molding squash in the garden, which all seem to vanish by the time the snow melts. 

So how do we explain their disappearance? To investigate this mystery we peek into the fascinating world of decomposition. We love to observe the life cycles of organisms on our trails, and you can too! Perhaps you have some experience with composting, either on a Frost Valley school trip, at a Frost Valley weekend retreat, or with your own home compost but have you had the chance to observe the process of decomposition?

Decomposers; such as fungi, bacteria, insects, worms, and protists eat dead material and in doing so break it down into the nutrients needed for fertile soil. Though some decomposers can’t be seen with the naked eye, there are decomposers in bright colors or funky shapes all around us. How many decomposers do you think you could spot in your backyard or on a nearby trail?

To explore the mystery of what happens to the leaves after they fall, try composting a pile of leaves. A clear plastic bin with air holes poked through it works well for this experiment. To create rich soil that can be used in potted plants or in a garden come springtime, try shredding the leaves before composting them and adding food scraps, worms, or a bit of soil as well. Stirring the compost every couple weeks helps to create air flow and gives an opportunity to see what’s happening inside the compost.

We hope that you, and the students in your life, can use this activity to remain curious, observant, and connected to the natural world this fall. We look forward to seeing you again soon at Frost Valley YMCA!